Light emitting apparatus

ABSTRACT

A light emitting device including a contact layer, a blocking layer over the contact layer, a protection layer adjacent the blocking layer, a light emitter over the blocking layer, and an electrode layer coupled to the light emitter. The electrode layer overlaps the blocking layer and protection layer, and the blocking layer has an electrical conductivity that substantially blocks flow of current from the light emitter in a direction towards the contact layer. In addition, the protection layer may be conductive to allow current to flow to the light emitter or non-conductive to block current from flowing from the light emitter towards the contact layer.

The present application claims priority of Korean Patent ApplicationsNo. 10-2009-0121739 filed on Dec. 9, 2009, No. 10-2009-0121740 filed onDec. 9, 2009, and No. 10-2010-0010048 filed on Feb. 3, 2010, which arehereby incorporated herein by reference.

BACKGROUND

1. Field

One or more embodiments described herein relate to emission of light.

2. Background

Light emitting diodes (LED) have advantages in terms of cost and powerconsumption compared to fluorescent and incandescent lamps. For thisreason, LEDs are used in liquid crystal displays, electric bulletinboards and street lamps. In spite of their technological superiority,improvements are still needed.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagram of a first embodiment of a light emitting device.

FIGS. 2 to 10 are diagrams showing steps included in one embodiment of amethod of manufacturing a light emitting device.

FIG. 11 is a diagram of a second embodiment of a light emitting device.

FIG. 12 is a diagram of a third embodiment of a light emitting device.

FIG. 13 is a diagram showing one example of planar-shape electrodes thatmay be used in a light emitting device according to any of theaforementioned embodiments.

FIG. 14 is a diagram of another example of planar-shape electrodes thatmay be used in a light emitting device according to the aforementionedembodiments.

FIG. 15 is a diagram of another example of planar-shape electrodes thatmay be used in a light emitting device according to the aforementionedembodiments.

FIG. 16 is a diagram of another example of planar-shape electrodes thatmay be used in a light emitting device according to the aforementionedembodiments.

FIG. 17 is a diagram of another example of planar-shape electrodes thatmay be used in a light emitting device according to the aforementionedembodiments.

FIG. 18 is a diagram of a comparative embodiment of an electrode.

FIG. 19 is a diagram showing the electrode in FIG. 15.

FIG. 20 is a diagram comparing light output of a light emitting deviceincluding the electrode of the embodiment in FIG. 13 with a lightemitting device including the electrode of the comparative embodimentshown in FIG. 18.

FIG. 21 is a diagram of an embodiment of a light emitting device packageincluding one of the aforementioned embodiments of the light emittingdevice.

FIG. 22 is a diagram of an embodiment of a backlight unit including thelight emitting device package of FIG. 21 and/or one of theaforementioned embodiments of the light emitting device.

FIG. 23 is a diagram of an embodiment of a lighting unit including oneof the aforementioned embodiments of the light emitting device or devicepackage.

DETAILED DESCRIPTION

FIG. 1 shows a first embodiment of a light emitting device that includesa conductive support substrate 175, a bonding layer 170 on theconductive support substrate 175, a reflective layer 160 on the bondinglayer 170, an ohmic contact layer 150 on the reflective layer 160, aprotection layer 140 at a periphery portion on the bonding layer 170, alight emitting structure layer 135 producing light on the ohmic contactlayer 150 and the protection layer 140, and an electrode layer 115 onthe light emitting structure layer 135.

The conductive support substrate 175 supports the light emittingstructure layer 135 and supplies power to the light emitting structurelayer 135 together with the electrode 115. For example, the conductivesupport substrate 175 may include at least one of Cu, Au, Ni, Mo, orCu—W and one or more carrier wafers such as, for example, Si, Ge, GaAs,ZnO, SiC, GaN, Ga2O3.

The bonding layer 170 may be formed on the conductive support substrate175, at a location under reflective layer 160 and protection layer 140.The bonding layer 170 is in contact with the reflective layer 160, theohmic contact layer 150, and the protection layer 140 such that thereflective layer 160, the ohmic contact layer 150, and the protectionlayer 140 are bonded to the conductive support substrate 175.

The bonding layer 170 is formed to bond the conductive support substrate175. Therefore, the bonding layer 170 is not necessarily formed, whenthe conductive support substrate 175 are plated or deposited, such thatthe bonding layer 170 may be selectively formed. The bonding layer 170includes barrier metal or bonding metal and, for example, may include atleast one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag or Ta.

The reflective layer 160 may be formed on the bonding layer 170, and mayserve to improve light extraction efficiency by reflecting incidentlight from the light emitting structure layer 135. The reflective layer160 may be made of metal or alloys which include, for example, at leastone of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au or Hf. Further, thereflective layer 160 may be formed in a multi-layer structure usingmetal or alloys and a light transmissive conductive material, such asIZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO. The reflective layer 160 isprovided to increase light efficiency and may not necessarily be formed.

The ohmic contact layer 150 may be formed on the reflective layer 160 inohmic contact with the second conductive semiconductor layer 130 toallow power to be smoothly supplied to the light emitting structurelayer 135. The ohmic contact layer may be formed, for example, of atleast any one of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO.

According to one embodiment, the ohmic contact layer 150 is selectivelymade of a light transmissive layer and metal, and may be implemented inone layer or a multi-layer structure from one or more of ITO (indium tinoxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tinoxide), GZO (gallium zinc oxide), IrOx, RuOx, RuOx/ITO, Ni, Ag,Ni/IrOx/Au, or Ni/IrOx/Au/ITO.

The ohmic contact layer 150 is provided to smoothly inject carriers intothe second conductive semiconductor layer 130 and may not be necessarilyformed. For example, the material used for the reflective layer 160 maybe a material that is in ohmic contact with the second conductivesemiconductor layer 130. The carriers that are injected into the secondconductive semiconductor layer 130 may not be largely different fromwhen the ohmic contact layer 150 is formed.

A current blocking layer (CBL) 145 may be formed in discrete orindividual sections between the ohmic contact layer 150 and the secondconductive semiconductor layer 130. The top of each section of thecurrent blocking layer 145 is in contact with the second conductivesemiconductor layer 130 and the bottom and sides of the current blockinglayer 145 is in contact with the ohmic contact layer 150.

The current blocking layer 145 may at least partially overlap theelectrode layer 115, and serves to increase current concentration in thelight-emitting structure layer 135. This current concentration functionallows the distance between the electrode layer 115 and the conductivesupport substrate 175 to be small, thereby improving light emittingefficiency of the light emitting device 100. Moreover, the currentconcentration function of the current blocking layer 145 allows largeamounts of current to flow in the light emitting structure layer 135.

Each section of the current blocking layer 145 may have a width that is0.9˜1.3 times the width of the electrode. If the electrode layer isformed from a plurality of electrodes (e.g., 115 a and 115 b), thewidths of the sections of the current blocking layer may be 0.9˜1.3times the width of one of electrodes 115 a or 115 b. According to oneembodiment, the sections of the current blocking layer 145 may havewidths that is 1.1˜1.3 times the width of the electrode layer, or one ofthe electrodes 115 a or 115 b in the case the electrode layer includes aplurality of electrodes.

The current blocking layer 145 may be made of a material that has lesselectrical conductivity than the reflective layer 160 or the ohmiccontact layer 150, a material that is in Schottky contact with thesecond conductive semiconductor layer 130, or an electric insulationmaterial For example, the current blocking layer 145 may include atleast one of ZnO, SiO2, SiON, Si3N4, Al2O3, TiO2, Ti, Al, or Cr.

As shown in FIG. 1, the current blocking layer 145 is formed between theohmic contact layer 150 and the second conductive semiconductor layer130. However, in an alternative embodiment, the current blocking layermay be formed between the reflective layer 160 and the ohmic contactlayer 150. According to another embodiment, a region where current hasdifficulty flowing may be formed by applying plasma treatment to thesecond conductive semiconductor layer 130, without forming the currentblocking layer 145. In this embodiment, the plasma-treated region may beused as a current blocking region performing a function like the currentblocking layer 145.

The protection layer 140 may be formed at a periphery portion on thebonding layer 170. When bonding layer 170 is not included, theprotection layer 140 may be formed at a periphery of the conductivesupport substrate 175.

The protection layer 140 can reduce deterioration in reliability of thelight emitting device 100 due to separation of the interface between thelight emitting structure layer 145 and the bonding layer 170.

The protection layer 140 may be a conductive layer or a non-conductivelayer. A conductive protection layer may be formed from a transparentconductive oxide film or may include at least one of Ti, Ni, Pt, Pd, Rh,Ir, or W.

The transparent conductive oxide film, for example, may be any one ofITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tinoxide), IAZO (indium aluminum zinc oxide), IGZO (indium gallium zincoxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO(antimony tin oxide), GZO (gallium zinc oxide).

A non-conductive protection layer may be formed from any one of avariety of non-conductive materials.

When included, the protection layer may prevent fragments from beinggenerated from the bonding layer 170, which may adhere and cause anelectrical short to form between second conductive semiconductor layer130 and active layer 120 or between active layer 120 and a firstconductive semiconductor layer 110, when isolation etching is applied todivide the light emitting structure layer 145 into unit chips in a chipseparation process. For this purpose, the protection layer may be madeof a material that is resistant to being broken or generating fragments.

If the protection layer has electrical conductivity (conductiveprotection layer), current can be injected into the light emittingstructure layer 135 through the conductive protection layer. Therefore,light can be effectively produced from the active layer on theconductive protection layer around the light emitting structure layer135.

Further, the conductive protection layer can reduce the operationalvoltage of the light emitting device by reducing the increase ofoperational voltage due to the current blocking layer 145. Theconductive protection layer may, for example, be made of the samematerial as the ohmic contact layer 150.

As an alternative to a conductive protection layer, a non-conductiveprotection layer may be used. This layer may be made of a materialhaving very low electrical conductivity. For example, the non-conductiveprotection layer 140 may be made of a material significantly smaller inelectrical conductivity than the reflective layer 160 or the ohmiccontact layer 150, a material that is in Schottky contact with thesecond conductive semiconductor layer 130, or an electric insulationmaterial. Examples of such a non-conductive material include ZnO orSiO2.

The non-conductive protection layer may serve to increase the distancebetween the bonding layer 170 and the active layer 120. Therefore, it ispossible to reduce the possibility of electric short between the bondinglayer 170 and the active layer 120.

In addition, the non-conductive protection layer prevents fragments frombeing generated from the bonding layer 170, which may adhere to andcause an electrical short to form between second conductivesemiconductor layer 130 and an active layer 120 or between the activelayer 120 and a first conductive semiconductor layer 110, when isolationetching is applied to divide the light emitting structure layer 145 intounit chips in a chip separation process.

Further, the non-conductive protection layer is made of a material thatis resistant to being broken or which forms fragments or a materialhaving electrical conductivity that does not cause an electric short toform, even if it is slightly broken into a small amount of fragments, inthe isolation etching.

The light emitting structure layer 135 may be formed on the ohmiccontact layer 150 and the protection layer 140. The sides of the lightemitting structure layer 135 may be inclined in the isolation etching toallow for separation into unit chips. The inclined surface may at leastpartially overlap the protection layer 140.

A portion of the top of the protection layer 140 may be exposed by theisolation etching. Therefore, the protection layer 140 may be formed tooverlap the light emitting structure layer 135 at a predetermined regionand not to overlap the light emitting structure layer 135 at anotherother region.

The first conductive semiconductor layer 110 may be an n-type layer of amaterial having a composition formula, In_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1,0≦y≦1, 0≦x+y≦1), for example, InAlGaN, GaN, AlGaN, AlInN, InGaN, AlN, orInN.

The active layer 120 is a layer emitting light, using a band gapdifference of an energy band according to the material of the activelayer 120, when electrons (or holes) injected through the firstconductive semiconductor layer 110 combine with the holes (or electrons)injected through the second conductive semiconductor layer 130.

The active layer 120 may be formed in any one of a single quantum well,a multi-quantum well (MQW), a quantum point, or quantum line structure,but other structures are also possible.

According to one embodiment, the active layer is made of a semiconductormaterial having the composition formula, InxAlyGa1−x−yN (0≦x≦1, 0≦y≦1,0≦x+y≦1). When the active layer 120 is formed in a multi-quantum wellstructure, the active layer 120 may be formed by stacking a plurality ofwell layers and a plurality of barrier layers, for example, in the orderof InGaN well layer/GaN barrier layer.

A clad layer (not shown) doped with an n-type or p-type dopant may beformed on and/or under the active layer 120, and may be implemented byan AlGaN layer or an InAlGaN layer.

The second conductive semiconductor layer 130 may be implemented by, forexample, a p-type semiconductor layer selected from a semiconductormaterial having the composition formula, InxAlyGa1−x−yN (0≦x≦2, 0≦y≦1,0≦x+y≦1), for example InAlGaN, GaN, AlGaN, InGaN, AlInN, AlN, or InN,and may be doped with a p-type dopant, such as Mg, Zn, Ca, Sr, or Ba.

The first conductive semiconductor layer 110 may be a p-typesemiconductor layer and the second conductive semiconductor layer 130may include an n-type semiconductor layer.

Further, a third conductive semiconductor layer (not shown) including ann-type or a p-type semiconductor layer may be formed on the secondconductive semiconductor layer 130. Accordingly, the light emittingstructure layer 135 may have at least any one of np, pn, npn, or pnpjunction structures. Further, the doping concentration in the firstconductive semiconductor layer 110 and the second conductivesemiconductor layer 130 may be uniform or non-uniform. That is, thestructure of the light emitting structure layer 130 may be modified invarious ways and is not limited to those described herein.

The light emitting structure layer 135 including the first conductivesemiconductor layer 110, the active layer 120, and the second conductivesemiconductor layer 130 may be formed in various structures and is notlimited to the structures of the light emitting structure layer 130which are exemplified in the illustrative embodiments described herein.

The electrode layer 115 is formed on the top of the light emittingstructure layer 135 and may be divided in a predetermined pattern. Aroughness pattern 112 may be formed on the top of the first conductivesemiconductor layer 110 to increase light extraction efficiency.Accordingly, a roughness pattern may be formed on top of the electrodelayer 115.

More specifically, electrode layer 115 may be in contact with the top ofthe first conductive semiconductor layer 110, and may be formed bystacking at least one pad unit and at least one branch-shaped electrodeunit in the same or a different structure.

The electrode layer 115 may include one or more outer electrodes 115 a,one or more an inner electrodes 115 b, and a pad unit (115 c in FIG.13). That is, the electrode unit may be composed of the outerelectrode(s) 115 a and the inner electrode(s) 115 b.

The electrode layer 115 may overlap the protection layer 140 and thecurrent blocking layer 145, at least at a predetermined portion. Forexample, the outer electrode 115 a may perpendicularly overlap theprotection layer 140 and the inner electrode 115 b may perpendicularlyoverlap the current blocking layer 145. The outer electrode 115 a mayperpendicularly overlap the protection layer 140, when the currentblocking layer 145 is not formed.

Since the protection layer overlaps the electrode 115, when theprotection layer is a conductive protection layer, a large amount ofcurrent may be allowed to flow in the active layer 120 above theconductive protection layer. Therefore, light is emitted through alarger area from the active layer 120, such that the light efficiency ofthe light emitting device can be increased. Further, the operationalvoltage of the light emitting device 100 can be reduced.

When the protection layer 140 is a non-conductive protection layer, asmall amount of current flows in the active layer 120 above thenon-conductive protection layer, such that light may not be produced,and accordingly, the light efficiency of the light emitting device 100may be reduced. However, since the electrode layer 115 is positionedwhere it overlaps the non-conductive protection layer, more current maybe allowed to flow in the active layer 120 above the non-conductiveprotection layer. Therefore, light is emitted through a larger area fromthe active layer 120, such that the light efficiency of the lightemitting device can be increased.

A passivation layer 180 may be formed at least on the sides of the lightemitting structure layer 135. Further, the passivation layer 180 may beformed on top of the first conductive semiconductor layer 110 and theprotection layer 140. The passivation layer 180 may be made of, forexample, SiO2, SiOx, SiOxNy, Si3N4, or Al2O3 to electrically protect thelight emitting structure layer 135.

FIG. 13 shows one example of planar-shape electrodes that may beincluded in the light emitting device. A cross-sectional shape takenalong the line I-I′ is shown in FIG. 1. The electrode layer containingthe planar-shaped electrodes 115 is formed on the first conductivesemiconductor layer 110. The electrodes may include outer electrode 115a that extend along the edge of the first conductive semiconductor layer110 and inner electrode 115 b that connects the first portion of theouter electrode 115 a with the second portion of the outer electrode 115a. The inner electrode 115 b may be disposed inside a region surroundedby the outer electrode 115 a.

The outer electrode 115 a may include a first outer electrode 115 a 1, asecond outer electrode 115 a 2, a third outer electrode 115 a 3, and afourth outer electrode 115 a 4. Further, the inner electrode 115 b mayinclude a first inner electrode 115 b 1, a second inner electrode 115 b2, a third inner electrode 115 b 3, and a fourth inner electrode 115 b4.

The outer electrode 115 a may be at least partially formed within 50 μmfrom the outermost side of the top of the first conductive semiconductorlayer 110, and may be in contact with the passivation layer 180. Forexample, the first outer electrode 115 a 1, the second outer electrode115 a 2, the third outer electrode 115 a 3, and fourth outer electrode115 a 4 each may be at least partially disposed within 50 μm from theoutermost side of the top of the first conductive semiconductor layer110.

The outer electrode 115 a may be disposed in a rectangular shape withfour sides and four corners and includes the first outer electrode 115 a1 and the second outer electrode 115 a 2 which extend in a firstdirection, and the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 which extend in a second direction, which isperpendicular to the first direction.

The pad unit 115 c may include a first pad unit 115 c 1 and a second padunit 115 c 2, in which the first pad unit 115 c 1 may be positioned atthe joint of the first outer electrode 115 a 1 and the third outerelectrode 115 a 3 and the second pad unit 115 c 2 may be positioned atthe joint of the first outer electrode 115 a 1 and the fourth outerelectrode 115 a 4.

The inner electrode 115 b includes the first inner electrode 115 b 1,the second inner electrode 115 b 2, the third inner electrode 115 b 3which extend in the second direction and connect the first outerelectrode 115 a 1 with the second outer electrode 115 a 2, and thefourth inner electrode 115 b 4 that extends in the first direction andconnects the third outer electrode 115 a 3 with the fourth outerelectrode 115 a 4, which extend in the second direction.

The distance A between the first outer electrode 115 a 1 and the fourthinner electrode 115 b 4 may be larger than the distance B between thesecond outer electrode 115 a 2 and the fourth inner electrode 115 b 4.

Further, the distance C between the third outer electrode 115 a 3 andthe first inner electrode 115 b 1, the distance D between the firstinner electrode 115 b 1 and the second inner electrode 115 b 2, thedistance E between the second inner electrode 115 b 2 and the thirdinner electrode 115 b 3, and the distance F between the third innerelectrode 115 b 3 and the fourth outer electrode 115 a 4 may besubstantially the same.

Further, the width of at least a part of the outer electrode 115 a maybe larger than the width of the inner electrode 115 b

Further, the width of at least a part of the outer electrode 115 a maybe larger than the width of the other parts of the outer electrode 115a. For example, the first outer electrode 115 a 1 may be formed largerin width than the inner electrode 115 b and the first outer electrode115 a 1 may be formed larger in width than the second outer electrode115 a 2.

Further, the width adjacent to the first outer electrode 115 a 1 in thewidths of the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 may be larger than the width adjacent to the secondouter electrode 115 a 2. For example, the outer electrode 115 a and theinner electrode 115 b define a window-shaped opening, in which the widthof the outer electrode 115 a which is positioned at the wide portion ofthe opening may be larger than the width of the outer electrode which ispositioned at the narrow portion of the opening.

The inner electrode 115 b divides the inner region surrounded by theouter electrode 115 a into a plurality of regions. The region that isadjacent to the first outer electrode 115 a 1, which has the largestwidth, in the regions is larger in area than the region that is adjacentto the second outer electrode 115 a 2 having a smaller width.

Further, the inner electrode 115 b may be formed smaller in width thanthe outer electrode 115 a. For example, the first outer electrode 115 a1, and the portions of the third outer electrode 115 ta 3 and the fourthouter electrode 115 a 4, which are adjacent to the first outer electrode115 a 1, may be formed to have a 25˜35 μm width, the second outerelectrode 115 a 2, and the portions of the third outer electrode 115 a 3and the fourth outer electrode 115 a 4, which are adjacent to the secondouter electrode 115 a 2, may be formed to have a 15˜25 μm width, and theinner electrode 115 b may be formed to have a 5˜15 μm width.

The electrode layer 115 of the light emitting device according to theembodiment shown in FIG. 13 may be applied to the light emittingstructure layer 135 of which one side is 800˜1200 μm long. The lightemission area may be reduced by the electrode layer 115, when the lengthof at least one side is less than 800 μm, while current may not beeffectively supplied through the electrode layer 115, when the length ofat least one side if less than 1200 μm. For example, the electrode layer115 in FIG. 13 may be applied to the light emitting structure layer 135,which lengths and widths of 1000 μm.

The electrode layer 115 described above can reduce resistance and allowcurrent from effectively distributed, in comparison with the area thatthe electrode 115 occupies.

FIG. 14 shows another example of planar-shape electrodes that may beincluded in the light emitting device. The electrode layer is formed onthe first conductive semiconductor layer 110 and may include outerelectrode 115 a that extends along the edge on top of the firstconductive semiconductor layer 110 and inner electrode 115 b thatconnects the outer electrode 115 a.

The outer electrode 115 a includes a first outer electrode 115 a 1, asecond outer electrode 115 a 2, a third outer electrode 115 a 3, and afourth outer electrode 115 a 4. Further, the inner electrode 115 b mayinclude a first inner electrode 115 b 1, a second inner electrode 115 b2, and a third inner electrode 115 b 3.

The outer electrode 115 a may be at least partially formed within 50 μmfrom the outermost side of the first conductive semiconductor layer 110,and may be in contact with the passivation layer 180.

The outer electrode 115 a may be disposed in a rectangular shape withfour sides and four corners and include the first outer electrode 115 a1 and the second outer electrode 115 a 2 which extend in a firstdirection, and the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 which extend in a second direction, which isperpendicular to the first direction.

The pad unit 115 c may include a first pad unit 115 c 1 and a second padunit 115 c 2, in which the first pad unit 115 c 1 may be positioned atthe joint of the first outer electrode 115 a 1 and the third outerelectrode 115 a 3 and the second pad unit 115 c 2 may be positioned atthe joint of the first outer electrode 115 a 1 and the fourth outerelectrode 115 a 4.

The inner electrode 115 b includes first inner electrode 115 b 1 andsecond inner electrode 115 b 2 which extend in the second direction andconnect first outer electrode 115 a 1 with second outer electrode 115 a2, and third inner electrode 115 b 3 that extends in the first directionand connects the third outer electrode 115 a 3 with the fourth outerelectrode 115 a 4, which extend in the second direction.

The distance A between the first outer electrode 115 a 1 and the thirdinner electrode 115 b 3 may be larger than the distance B between thesecond outer electrode 115 a 2 and the third inner electrode 115 b 3.

Further, the distance C between the third outer electrode 115 a 3 andthe first inner electrode 115 b 1, the distance D between the firstinner electrode 115 b 1 and the second inner electrode 115 b 2, and thedistance E between the second inner electrode 115 b 2 and the fourthouter electrode 115 a 4 may be substantially the same.

Further, the width of at least a portion of the outer electrode 115 amay be larger than the width of the inner electrode 115 b.

Further, the width of at least a part of the outer electrode 115 a maybe larger than the width of the other parts of the outer electrode 115a. For example, the first outer electrode 115 a 1 may be formed largerin width than the inner electrode 115 b and the first outer electrode115 a 1 may be formed larger in width than the second outer electrode115 a 2.

Further, the width adjacent to the first outer electrode 115 a 1 in thewidths of the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 may be larger than the width adjacent to the secondouter electrode 115 a 2.

The inner electrode 115 b divides the inner region surrounded by theouter electrode 115 a into a plurality of regions. The region that isadjacent to the first outer electrode 115 a 1, which has the largestwidth, in the regions are larger in area than the region that isadjacent to the second outer electrode 115 a 2.

The electrode layer 115 of the light emitting device shown in FIG. 14may be applied to the light emitting structure layer 135, of which oneside is 800˜1200 μm long. The light emission area may be reduced by theelectrode 115, when the length of at least one side is less than 800 μm,while current may not be effectively supplied through the electrodelayer 115 when the length of at least one side if less than 1200 μm. Forexample, the electrode layer 115 in FIG. 14 may be applied to the lightemitting structure layer 135, which lengths and widths of 1000 μm.

The electrode 115 described above can reduce resistance and allowcurrent from effectively distributed, in comparison with the area thatthe electrode 115 occupies.

FIG. 15 shows another example of planar-shape electrodes that may beincluded in the light emitting device. The electrode layer 115 is formedon the first conductive semiconductor layer 110 and may include outerelectrode 115 a that extends along the edge on top of the firstconductive semiconductor layer 110 and inner electrode 115 b thatconnect is the outer electrode 115 a.

The outer electrode 115 a includes a first outer electrode 115 a 1, asecond outer electrode 115 a 2, a third outer electrode 115 a 3, and afourth outer electrode 115 a 4. Further, the inner electrode 115 b mayinclude a first inner electrode 115 b 1 and a second inner electrode 115b 2.

The outer electrode 115 a may be at least partially formed within 50 μmfrom the outermost side of the first conductive semiconductor layer 110,and may be in contact with the passivation layer 180.

The outer electrode 115 a may be disposed in a rectangular shape withfour sides and four corners and may include the first outer electrode115 a 1 and the second outer electrode 115 a 2 which extend in a firstdirection, and the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 which extend in a second direction, which isperpendicular to the first direction.

The pad unit 115 c may include a first pad unit 115 c 1 and a second padunit 115 c 2, in which the first pad unit 115 c 1 may be positioned atthe joint of the first outer electrode 115 a 1 and the third outerelectrode 115 a 3 and the second pad unit 115 c 2 may be positioned atthe joint of the first outer electrode 115 a 1 and the fourth outerelectrode 115 a 4.

The inner electrode includes the first inner electrode 115 b 1 and thesecond inner electrode 115 b 2 which extend in the second direction andconnect the first outer electrode 115 a 1 and the second outer electrode115 a 2, which extend in the first direction.

The distance C between the third outer electrode 115 a 3 and the firstinner electrode 115 b 1, the distance D between the first innerelectrode 115 b 1 and the second inner electrode 115 b 2, and thedistance E between the second inner electrode 115 b 2 and the fourthouter electrode 115 a 4 may be substantially the same.

As described with reference to FIGS. 13 and 14, in the electrode layer115 shown in FIG. 15, the width of at least a part of the outerelectrode 115 a may be larger than the width of the inner electrode 115b, while the width of at least a part of the outer electrode 115 a maybe larger than the other parts of the outer electrode 115 a. Forexample, the first outer electrode 115 a 1 may be formed larger in widththan the inner electrode 115 b and the first outer electrode 115 a 1 maybe formed larger in width than the second outer electrode 115 a 2. Asshown in FIG. 15, the outer electrode 115 a and the inner electrode 115b may be formed to have the same width.

The electrode layer 115 of the light emitting device shown in FIG. 15may be applied to the light emitting structure layer 135, of which oneside is 800˜1200 μm long. The light emission area may be reduced by theelectrode 115, when the length of at least one side is less than 800 μm,while current may not be effectively supplied through the electrodelayer 115, when the length of at least one side if less than 1200 μm.For example, the electrode layer 115 shown in FIG. 15 may be applied tothe light emitting structure layer 135, which lengths and widths of 1000μm.

The electrode layer 115 described above can reduce resistance and allowcurrent from effectively distributed, in comparison with the area thatthe electrode 115 occupies.

FIG. 16 shows another example of planar-shape electrodes that may beincluded in the light emitting device. The electrode layer 115 is formedon the first conductive semiconductor layer 110 and may include outerelectrode 115 a extending along the edge on top of the first conductivesemiconductor layer 110 and inner electrode 115 b connecting the outerelectrode 115 a with the outer electrode 115 a.

The outer electrode 115 a includes a first outer electrode 115 a 1, asecond outer electrode 115 a 2, a third outer electrode 115 a 3, and afourth outer electrode 115 a 4.

The outer electrode 115 a may be at least partially formed within 50 μmfrom the outermost side of the first conductive semiconductor layer 110,and may be in contact with the passivation layer 180.

The outer electrode 115 a may be disposed in a rectangular shape withfour sides and four corners and may include the first outer electrode115 a 1 and the second outer electrode 115 a 2 which extend in a firstdirection, and the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 which extend in a second direction, which isperpendicular to the first direction.

The pad unit 115 c may be positioned at the joint of the first externalelectrode 115 a 1 and the inner electrode 115 b. The inner electrode 115b extends in the second direction and connects the first outer electrode115 a 1 with the second outer electrode 115 a 2, which extend in thefirst direction.

The distance C between the third outer electrode 115 a 3 and the innerelectrode 115 b may be substantially the same as the distance D betweenthe inner electrode 115 b and the fourth outer electrode 115 a 4.

As described with reference to FIGS. 13 and 14, in the electrode 115shown in FIG. 16, the width of at least a part of the outer electrode115 a may be larger than the width of the inner electrode 115 b, whilethe width of at least a part of the outer electrode 115 a may be largerthan the other parts of the outer electrode 115 a.

For example, the first outer electrode 115 a 1 may be formed larger inwidth than the inner electrode 115 b and the first outer electrode 115 a1 may be formed larger in width than the second outer electrode 115 a 2.As shown in FIG. 16, the outer electrode 115 a and the inner electrode115 b may be formed to have the same width.

The electrode layer 115 of the light emitting device in FIG. 16 may beapplied to the light emitting structure layer 135 of which one side is400˜800 μm long. The light emission area may be reduced by the electrodelayer 115, when the length of at least one side is less than 400 μm,while current may not be effectively supplied through the electrodelayer 115 when the length of at least one side if less than 800 μm. Forexample, the electrode 115 shown in FIG. 16 may be applied to the lightemitting structure layer 135, which lengths and widths of 600 μm.

The electrode 115 described above can reduce resistance and allowcurrent from effectively distributed, in comparison with the area thatthe electrode 115 occupies.

FIG. 17 shows another example of planar-shape electrodes that may beused in the light emitting device. The electrode layer 115 is formed onthe first conductive semiconductor layer 110 and may include outerelectrode 115 a that extends along the edge on top of the firstconductive semiconductor layer 110 and inner electrode 115 b thatconnect with the outer electrode 115 a.

The outer electrode 115 a includes a first outer electrode 115 a 1, asecond outer electrode 115 a 2, a third outer electrode 115 a 3, and afourth outer electrode 115 a 4. Further, the inner electrode 115 b mayinclude a first inner electrode 115 b 1 and a second inner electrode 115b 2.

The outer electrode 115 a may be at least partially formed within 50 μmfrom the outermost side of the first conductive semiconductor layer 110,and may be in contact with the passivation layer 180.

The outer electrode 115 a may be disposed in a rectangular shape withfour sides and four corners and includes the first outer electrode 115 a1 and the second outer electrode 115 a 2 which extend in a firstdirection, and the third outer electrode 115 a 3 and the fourth outerelectrode 115 a 4 which extend in a second direction, which isperpendicular to the first direction.

The pad unit 115 c may be positioned at the joint of the first externalelectrode 115 a 1 and the first inner electrode 115 b 1.

The inner electrode 115 b includes the first inner electrode 115 b 1that extends in the second direction and connects the first outerelectrode 115 a 1 with the second outer electrode 115 a 2, and thesecond inner electrode 115 b 2 that extends in the first direction andconnects the third outer electrode 115 a 3 with the fourth outerelectrode 115 a 4, which extend in the second direction.

The distance A between the first outer electrode 115 a 1 and the secondinner electrode 115 b 2 may be larger than the distance B between thesecond outer electrode 115 a 2 and the second inner electrode 115 b 2.

Further, the distance C between the third outer electrode 115 a 3 andthe first inner electrode 115 b 1 may be substantially the same as thedistance D between the first inner electrode 115 b 1 and the fourthouter electrode 115 a 4.

As described with reference to FIGS. 13 and 14, in the electrode layer115 in FIG. 17, the width of at least a part of the outer electrode 115a may be larger than the width of the inner electrode 115 b, while thewidth of at least a part of the outer electrode 115 a may be larger thanthe other parts of the outer electrode 115 a.

For example, the first outer electrode 115 a 1 may be formed larger inwidth than the inner electrode 115 b and the first outer electrode 115 a1 may be formed larger in width than the second outer electrode 115 a 2.As shown in FIG. 17, the outer electrode 115 a and the inner electrode115 b may be formed to have the same width.

The inner electrode 115 b divides the inner region surrounded by theouter electrode 115 a into a plurality of regions. The region that isadjacent to the first outer electrode 115 a 1 in the regions is largerin area than the region that is adjacent to the second outer electrode115 a 2.

The electrode layer 115 of the light emitting device in FIG. 17 may beapplied to the light emitting structure layer 135 of which one side is400˜800 μm long. The light emission area may be reduced by the electrode115, when the length of at least one side is less than 400 μm, whilecurrent may not be effectively supplied through the electrode 115, whenthe length of at least one side if less than 800 μm. For example, theelectrode 115 shown in FIG. 17 may be applied to the light emittingstructure layer 135, which lengths and widths of 600 μm.

The electrode 115 described above can reduce resistance and allowcurrent from effectively distribution, compared to the area thatelectrode 115 occupies.

FIGS. 18 and 19 show examples of light output in accordance witharrangement of electrodes in a light emitting device according to one ormore of the aforementioned embodiments. More specifically, an electrodeaccording to a comparative arrangement is shown in FIG. 18 and anelectrode described with reference to FIG. 15 is shown in FIG. 19.

The electrode layer 115 in FIG. 18 and the electrode layer 115 in FIG.19 have substantially the same shape. However, the electrode layer 115according to the comparative arrangement in FIG. 18 is disposed at adistance above 50 μm from the outermost side of the top of the firstconductive semiconductor layer 110, while the electrode 115 shown inFIG. 19 is at least partially disposed within 50 μm from the outermostside of the top of the first conductive semiconductor layer 110, incontact with the passivation layer 180.

According to an experiment, it could be seen that light output of 282 mWwas measured in the comparative arrangement in FIG. 18 and light outputof 304 mW was measured in the embodiment in FIG. 19, such that the lightoutput was improved by 8%, when only the arrangement of electrodes 115is changed, with the other conditions kept the same.

FIG. 20 shows a comparison of light outputs of a light emitting deviceincluding the electrode embodiment in FIG. 13 with a light emittingdevice including the electrode of the comparative arrangement in FIG.18.

According to an experiment, it can be seen that the light output of thelight emitting device including the electrodes in FIG. 13 is excellent,compared with the light output of the light emitting device includingthe electrodes of the comparative arrangement in FIG. 18, when theelectrodes 115 are arranged as illustrated in FIGS. 13 and 18, with theother conditions kept the same.

FIG. 11 shows a second embodiment of a light emitting device which has astructure similar to the light emitting device according to the firstembodiment. However, in the light emitting device according to thesecond embodiment, the ohmic contact layer 150 extends to the sides ofthe light emitting device. That is, the ohmic contact layer 150 isdisposed on the sides and the bottom of the protection layer 140, andthe protection layer 140 and bonding layer 170 are spaced by the ohmiccontact layer 150.

FIG. 12 shows a third embodiment of a light emitting device which has astructure similar to the light emitting device according to the firstembodiment. However, in the light emitting device according to the thirdembodiment, the reflective layer 160 extends to the sides of the lightemitting device.

That is, the reflective layer 160 is disposed on the bottoms of theprotection layer 140 and the ohmic layer 150, and the protection layer140 and the bonding layer 170 are spaced by the ohmic contact layer 160.The protection layer 140 is partially formed on the reflective layer160. The reflective layer 160 can increase light efficiency by moreeffectively reflecting the light produced from the active layer 120,when being formed on the entire top of the bonding layer 170. Though notshown, the ohmic contact layer 150 and the reflective layer 160 may bedisposed to extend to the sides of the light emitting device.

FIGS. 2 to 10 show results produced by different steps included in oneembodiment of a method for manufacturing a light emitting device.Referring to FIG. 2, the light emitting structure layer 135 is formed ona growth substrate 101. The growth substrate 101 may be made of, forexample, at least one of sapphire (Al2O3), SiC, GaAs, GaN, ZnO, Si, GaP,InP, or Ge.

The light emitting structure layer 135 may be formed by sequentiallygrowing the first conductive semiconductor layer 110, the active layer120, and the second conductive semiconductor layer 130 on the growthsubstrate 101. The light emitting structure layer 135 may be formed byMOCVD (Metal Organic Chemical Vapor Deposition), CVD (Chemical VaporDeposition), PECVD (Plasma-Enhanced Chemical Vapor Deposition), MBE(Molecular Beam Epitaxy), and HVPE (Hydride Vapor Phase Epitaxy), and isnot limited thereto.

A buffer layer and/or an undoped nitride layer may be formed between thelight emitting structure layer 135 and the growth substrate 101 toreduce a lattice constant difference.

Referring to FIG. 3, the protection layer 140 is formed on the lightemitting structure layer 135, corresponding to a unit chip region. Theprotection layer may be formed around the unit chip area by a maskpattern, and may be formed using various deposition methods.

In particular, when the protection layer 140 is a conductive protectionlayer and includes at least one of Ti, Ni, Pt, Pd, Rh, Ir, or W, theprotection layer 140 can be formed to have high concentration bysputtering, such that it is not broken into fragments in isolationetching.

Referring to FIG. 4, the current blocking layer 145 may be formed on thesecond conductive layer 130. The current blocking layer 145 may beformed by a mask pattern. For example, the current blocking layer 145may be formed by a mask pattern, after a SiO2 layer is formed on thesecond conductive semiconductor layer 130.

When the protection layer 140 is a non-conductive protection layer, theprotection layer 140 and the current blocking layer 145 may be made ofthe same material. In this case, it is possible to simultaneously formthe protection layer 140 and the current blocking layer 145 in oneprocess, not in separate processes.

For example, the protection layer 140 and the current blocking layer 145may be simultaneously formed by a mask pattern, after a SiO2 layer isformed on the second conductive semiconductor layer 130.

Referring to FIGS. 5 and 6, the ohmic contact layer 150 is formed on thesecond conductive semiconductor layer 130 and the current blocking layer145, and then the reflective layer 160 may be formed on the ohmiccontact layer 150.

When the protection layer 150 is a conductive protection layer, theohmic contact layer 150 may be made of the same material as theprotection layer 140, in which the protection layer 140 and the ohmiccontact layer 150 may be simultaneously formed, after the currentblocking layer 145 is formed on the second conductive semiconductorlayer 130. The ohmic contact layer 150 and the reflective layer may beformed, for example, using any one of E-beam deposition, sputtering, orPECVD (Plasma Enhanced Chemical Vapor Deposition).

The area where the ohmic contact layer 150 and the reflective layer 160are formed may be variously selected and the light emitting devicesaccording to the other embodiments described with reference to FIGS. 11and 12 may be formed in accordance with the area where the ohmic contactlayer 150 and/or the reflective layer 160 are formed.

Referring to FIG. 7, the conductive support substrate 175 is formedabove the reflective layer 160 and the protection layer 140 with thebonding layer 170 therebetween. The bonding layer 170 is in contact withthe reflective layer 160, the ohmic contact layer 150, and thepassivation layer 140 such that the bonding force can be strengthenedbetween reflective layer 160, the ohmic contact layer 150, and thepassivation layer 140.

The conductive support substrate 175 is attached to the bonding layer170. Although it is exemplified in the embodiment that the conductivesupport substrate 175 is bonded by the bonding layer 170, the conductivesupport substrate 175 may be plated or deposited.

Referring to FIG. 8, the growth substrate 101 is removed from the lightemitting structure layer 135. The structure shown in FIG. 7 is turnedover in FIG. 8. The growth substrate 101 can be removed by laserlift-off or chemical lift-off.

Referring to FIG. 9, the light emitting structure layer 135 is dividedinto a plurality of light emitting structure layers 135 by applyingisolation etching to each unit chip. For example, the isolation etchingmay be performed by dry etching, such as ICP (Inductively CoupledPlasma).

Referring to FIG. 10, the passivation layer 180 is formed on theprotection layer 140 and the light emitting structure layer 135 and thepassivation layer 180 is selectively removed such that the top of thefirst conductive semiconductor layer 110 is exposed.

Further, a roughness pattern 112 is formed on the top of the firstconductive semiconductor layer 110 to improve light extractionefficiency and the electrode 115 is formed on the roughness pattern 112.The roughness pattern 112 may be formed by wet etching or dry etching.

Further, a plurality of light emitting devices can be manufactured bydividing the structure in unit chip regions, using a chip separationprocess. The chip separation process may include, for example, a brakingprocess that separate the chips by applying physical force with a blade,a laser scribing process that separates the chips by radiating laser tothe chip interfaces, and an etching including wet etching and dryetching, but it is not limited thereto.

FIG. 21 shows a cross-sectional view of one embodiment of a lightemitting device package that includes one or more light emitting devicesaccording to any of the aforementioned embodiments.

Referring to FIG. 21, a light emitting device package according to anembodiment includes a package body 10, a first electrode 31 and a secondelectrode 32 which are installed at the package body 10, a lightemitting device 100 installed in the package body 10 and electricallyconnect the first electrode 31 with the second electrode 32, and amolding member 40 covering the light emitting device 100.

The package body 10 may include a silicon material, a synthetic resinmaterial, and a metal material, and may have a cavity with inclinedsides.

The first electrode 31 and the second electrode 32 are electricallydisconnected and supply power to the light emitting device 100. Further,the first electrode 31 and the second electrode 32 can increase lightefficiency by reflecting light produced from the light emitting device100, and may function of discharging heat generated from the lightemitting device 100 to the outside.

The light emitting device 100 may be installed on the package body 10 oron the first electrode 31 and the second electrode 32.

The light emitting device 100 may be electrically connected with thefirst electrode 31 and the second electrode 32 by any one of a wire way,a flip-chip way, and a die bonding way. Exemplified in the embodiment,the light emitting device 100 is electrically connected with the firstelectrode 31 by a wire 50 and electrically connected with the secondelectrode 32 by direct contact.

The molding member 40 can protect the light emitting device 100 bycovering the light emitting device 100. Further, fluorescent substancesmay be included in the molding member 40 to change the wavelength oflight emitted from the light emitting device 100.

According to one embodiment, a plurality of light emitting devicepackages are arrayed on the substrate, and a light guide panel, a prismsheet, a diffusion sheet, and a fluorescent sheet, which are opticalcomponents, may be disposed in the path of the light emitted from thelight emitting device packages. The light emitting device package, thesubstrate, and the optical components may function as a backlight unitor a lighting unit, and for example, the light system may include abacklight unit, a lighting unit, an indicator, a lamp, and a streetlamp.

FIG. 22 shows one embodiment of a backlight unit 1100 that includes alight emitting device or a light emitting device package. The backlightunit 1100 shown in FIG. 22 is an example of a lighting system and notlimited thereto.

Referring to FIG. 22, the backlight unit 1100 may include a bottom frame1140, a light guide member 1120 disposed inside the bottom frame 1140,and a light emitting module 1110 disposed at least on one side or thebottom of the light guide member 1120. Further, a reflective sheet 1130may be disposed under the light guide member 1120.

The bottom frame may be formed in a box shape with the top open toaccommodate the light guide member 1120, the light emitting module 1110,and the reflective sheet 1130 and may be made of metal or resin, forexample.

The light emitting module 1110 may include a substrate 700 and aplurality of light emitting device package 600 mounted on the substrate700. The light emitting device package 600 may provide light to thelight guide member 1120. Although it is exemplified in the embodimentthat the light emitting device packages 600 are mounted on the substrate700 in the light emitting module 1110, the light emitting device 100according to an embodiment may be directly mounted thereon.

As shown in the figures, the light emitting module 1110 may be disposedon at least any one of the inner sides of the bottom frame 1140, andaccordingly, light can be provided to at least one side of the lightguide member 1120. However, the light emitting module 1110 may bedisposed under the bottom frame 1140 to provide light to the bottom ofthe light guide member 1120, which can be modified in various ways inaccordance with design of the backlight unit 1100 and is not limitedthereto.

The light guide member 1120 may be disposed inside the bottom frame1140. The light guide member 1120 can convert the light provided fromthe light emitting module 1110 in surface light and guide it to adisplay panel (not shown).

The light guide member 1120 may be, for example, an LGP (Light GuidePanel). The light guide panel may be made of, for example, one of acrylresin, such as PMMA (polymethyl metaacrylate), and PET (polyethyleneterephthlate), PC (poly carbonate), COC, and PEN (polyethylenenaphthalate) resin.

An optical sheet 1150 may be disposed on the light guide member 1120.The optical sheet 1150 may includes, for example, at least one of adiffusion sheet, a light collecting sheet, a luminance increasing sheet,and a fluorescent sheet. For example, the optical sheet 1150 may beformed by stacking a diffusion sheet, a light collecting sheet, aluminance increasing sheet, and a fluorescent sheet. In thisconfiguration, diffusion sheet 1150 uniformly diffuses the lightradiated from light emitting module 1110 and diffused light can becollected to the display panel by the light collecting sheet.

In this configuration, the light from the light collecting sheet islight randomly polarized and the luminance increasing sheet can increasedegree of polarization of the light from the light collecting sheet. Thelight collecting sheet may be, for example, a horizontal or/and avertical prism sheet. Further, the luminance increasing sheet may be,for example, a dual brightness enhancement film. Further, the florescentsheet may be a light transmissive plate or film, which includesfluorescent substances.

A reflective sheet 1130 may be disposed under the light guide member1120. The reflective sheet 1130 can reflect light emitted through thebottom of the light guide member 1120, toward the exit surface of thelight guide member 1120. The reflective sheet 1130 may be made of resinhaving high reflective ratio, for example PET, PC, or PVC resin.

FIG. 23 shows one embodiment of a lighting unit 1200 that includes alight emitting device or a light emitting device package according toany of the aforementioned embodiments. The lighting unit 1200 shown inFIG. 23 is an example of a lighting system.

Referring to FIG. 23, the lighting unit 1200 may include a case body1210, a lighting module installed to the case body 1210, and aconnecting terminal 1220 installed to the case body 1210 and providedwith power from an external power supply. It is preferable that the casebody 1210 is made of a material having good heat dissipation propertiesand may be made of metal or resin, for example.

The light emitting module 1230 may include a substrate 700 and at leastone light emitting device package 600 mounted on the substrate 700.Although it is exemplified in the embodiment that the light emittingdevice packages 600 are mounted on the substrate 700 in the lightemitting module 1110, the light emitting device 100 according to anembodiment may be directly mounted thereon.

The substrate 700 may be formed by printing a circuit pattern on aninsulator and may include, for example, a common PCB (Printed CircuitBoard), a metal core PCB, a flexible PCB, and a ceramic PCB.

Further, the substrate 700 is made of a material efficiently reflectinglight, or the surface may have a color efficiently reflecting light,such as white and silver.

At least one of the light emitting device package 600 may be mounted onthe substrate 700. The light emitting device packages 600 each mayinclude at least one LED (Light Emitting Diode). The light emittingdiodes may include color light emitting diodes that produce colors, suchas red, green, blue, or white, and UV light emitting diodes that produceultraviolet rays.

The light emitting module 1230 may be disposed to have variouscombinations of light emitting diodes to achieve the impression of acolor and luminance. For example, white light emitting diodes, red lightemitting diodes, and green light emitting diodes may be combined toensure high CRI.

Further, a fluorescent sheet may be further disposed in the travelingpath of the light emitted from the light emitting module 1230 andchanges the wavelength of the light emitted from the light emittingmodule 1230. For example, when the light emitted from the light emittingmodule 1230 has a blue wavelength band, yellow fluorescent substancesmay be included in the fluorescent sheet, and the light emitted from thelight emitting module 1230 is finally shown as white light through thefluorescent sheet.

The connecting terminal 12220 can supply power by being electricallyconnected with the light emitting module 1230. According to theembodiment shown in FIG. 23, the connecting terminal 1220 is turned andinserted in an external power supply, like a socket, but is not limitedthereto. For example, the connecting terminal 1220 may be formed in apin shape to be inserted in an external power supply or may be connectedto the external power supply by a wire.

Since at least any one of the light guide member, a diffusion sheet, alight collecting sheet, a luminance increasing sheet, and a fluorescentsheet is disposed in the traveling path of the light emitted form thelight emitting module in the lighting system as described above, it ispossible to achieved desired optical effects.

As described above, the lighting system can achieve high lightefficiency and reliability, by including light emitting devices havingreduced operational voltage and improved light efficiency or lightemitting packages.

One or more embodiments described herein provide a light emitting devicehaving reduced operational voltage, a light emitting devicemanufacturing method, a light emitting device package, and a lightingsystem. One or more of these embodiments further provide a lightemitting device having improved light efficiency, a light emittingdevice manufacturing method, a light emitting device package, and alighting system.

A light emitting device according to an embodiment includes: aconductive support substrate; a bonding layer on the conductive supportsubstrate; a reflective layer on the bonding layer; an ohmic contactlayer on the reflective layer; a current blocking layer on the ohmiccontact layer; a protection layer at a periphery portion on the bondinglayer; a light emitting structure layer on the current blocking layer,the ohmic contact layer, and the protection layer; and electrodes atleast partially overlapping the current blocking layer and theprotection layer, on the light emitting structure layer, in which theprotection layer is made of a material having electric conductivitylower than the reflective layer of the ohmic contact layer, an electricinsulation material, or a material that is in schottky contact with thelight emitting structure layer.

A light emitting device according to another embodiment includes: aconductive support substrate; a light emitting structure layer on theconductive support substrate; a conductive protection layer disposed ata periphery portion on the conductive support substrate and partiallydisposed between the conductive support substrate and the light emittingstructure layer; and electrodes disposed on the light emitting structurelayer and at least partially overlapping the conductive protectionlayer, in which the light emitting structure layer has inclined sides,and the inclined sides overlap the conductive protection layer.

A light emitting device according to another embodiment includes: aconductive support substrate; a light emitting structure layer on theconductive support substrate; a protection layer disposed at a peripheryportion on the conductive support substrate and partially disposedbetween the conductive support substrate and the light emittingstructure layer; and electrodes at least partially overlapping theprotection layer on the light emitting structure layer, in which theelectrodes includes outer electrodes, inner electrodes disposed insidethe outer electrodes and connecting the first portions and the secondportions of the outer electrodes, and pad units connected to the outerelectrodes.

According to another embodiment, a light emitting device includes acontact layer; a blocking layer over the contact layer; a protectionlayer adjacent the blocking layer; a light emitter over the blockinglayer; and an electrode layer coupled to the light emitter. Theelectrode layer overlaps the blocking layer and protection layer andwherein the blocking layer has an electrical conductivity thatsubstantially blocks flow of current from the light emitter in adirection towards the contact layer.

The blocking layer includes a plurality of spaced current blockingsegments, and current flows to the light emitter through areas betweenrespective pairs of the current blocking segments. The electrode layermay include a plurality of electrode segments aligned with respectiveones of the spaced current blocking segments.

The protection layer may be made of a conductive material and whereincurrent flows to the light emitter through the protection layer, andadditional current may flow to the light emitter in an area locatedbetween the protection layer and the blocking layer.

The blocking layer and the protection layer may be substantiallyco-planar, and the blocking layer may separate a first portion and asecond portion of the protection layer. The blocking layer may bealigned with a central region of the light emitter, and the first andsecond portions of the protection layer are aligned on either side ofthe central region. The protection layer may be between a bonding layerunder the light emitter.

In addition, the light emitter may have a top surface with apredetermined pattern, the pattern substantially corresponding to thepredetermined pattern of the top surface of the light emitter.

The width of the contact layer may be equal to or greater than a widthof the light emitter, and a reflective layer may be provided adjacentthe contact layer. A width of the reflective layer is less than a widthof the light emitter, or the width of the reflective layer is greaterthan a width of the light emitter.

The protection layer may be made of a non-conductive material and issubstantially coplanar with the blocking layer, and wherein currentflows into the light emitter through one or more spaces between theprotection layer and the blocking layer.

The blocking layer and/or protection may be made of a material having anelectrical conductivity lower than at least one of a reflective layer toreflect light from the light emitter, the contact layer, an electricinsulation material included in the light emitting device, or a materialthat is in Schottky contact with the light emitter.

The light emitter has inclined sides and wherein the inclined sidesoverlap the protection layer, and the electrode layer may include atleast two outer electrode segments; and one or more inner electrodesegments between the two outer electrode segments, wherein the two outerelectrode segments and one or more inner electrode segments are spacedfrom one another.

The two outer electrode segments and the one or more inner electrodesegments are substantially equally spaced, and the two outer electrodesegments and the one or more inner electrode segments are connected toone another to form a predetermined pattern. The predetermined patternincludes one or more substantially rectangular sections formed byconnections between the two outer electrode segments and the one or moreinner electrode segments. Also, one or more pad parts may be coupled tothe electrode layer.

According to another embodiment, light emitting device package mayinclude a package body, first and second electrode layers coupled to thepackage body; and a light emitting device according to claim 1electrically coupled to the first and second electrode layers.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments. Thefeatures of any one embodiment may be combined with the features of anyother embodiment.

Although embodiments have been described with reference to a number ofillustrative embodiments, numerous other modifications and embodimentscan be devised by those skilled in the art that will fall within thespirit and scope of the principles of this disclosure. Particularly,various variations and modifications are possible in the component partsand/or arrangements of the subject combination arrangement within thescope of the disclosure, the drawings and the appended claims. Inaddition to variations and modifications in the component parts and/orarrangements, alternative uses will also be apparent to those skilled inthe art.

1. A light emitting device comprising: a conductive support substrate; alight emitting structure layer on the conductive support substrate; aprotection layer provided on an outer periphery portion of theconductive support substrate, a portion of the protection layer beinginterposed between the conductive support substrate and the lightemitting structure layer; and an electrode having at least a portionoverlapping with the protection layer on the light emitting structurelayer, wherein the electrode includes an outer electrode, an innerelectrode provided in a region of the outer electrode and connecting afirst part of the outer electrode with a second part of the outerelectrode, and a pad unit connected to the outer electrode.
 2. The lightemitting device of claim 1, wherein at least a portion of the outerelectrode has a width greater than a width of the inner electrode. 3.The light emitting device of claim 1, wherein at least a portion of theouter electrode has a width of another portion of the outer electrode.4. The light emitting device of claim 1, wherein at least a portion ofthe electrode is provided within a distance of 50 μm from an upper sidesurface of the light emitting structure layer.
 5. The light emittingdevice of claim 1, further comprising a passivation layer formed on aside surface and a portion of a top surface of the light emittingstructure layer, wherein at least a portion of the electrode makescontact with the passivation layer.
 6. The light emitting device ofclaim 1, wherein the protection layer includes a conductive protectionlayer, and the conductive protection layer includes a transparentconductive oxide film or includes at least one selected from the groupconsisting of Ti, Ni, Pt, Pd, Rh, Ir, and W.
 7. The light emittingdevice of claim 1, wherein the protection layer includes anon-conductive protection layer, and the non-conductive protection layerincludes an electric insulation material or a material making schottkycontact with the light emitting structure layer.
 8. The light emittingdevice of claim 1, wherein the outer electrode includes first and secondouter electrodes extending in a first direction, and third and fourthouter electrodes extending in a second direction to be connected to thefirst and second outer electrodes, and wherein the inner electrodeincludes a first inner electrode interposed between the third and fourthouter electrodes and formed in the second direction to connect the firstouter electrode to the second outer electrode.
 9. The light emittingdevice of claim 1, wherein the outer electrode includes first and secondouter electrodes extending in a first direction, and third and fourthouter electrodes extending in a second direction to be connected to thefirst and second outer electrodes, and wherein the inner electrodeincludes a first inner electrode, which is interposed between the thirdand fourth outer electrodes and formed in the second direction toconnect the first outer electrode to the second outer electrode, and asecond inner electrode, which is interposed between the first and secondouter electrodes and formed in the first direction to connect the thirdouter electrode to the fourth outer electrode.
 10. The light emittingdevice of claim 9, wherein a distance between the first outer electrodeand the second inner electrode is greater than a distance between thesecond outer electrode and the second inner electrode.
 11. The lightemitting device of claim 1, wherein the outer electrode includes firstand second outer electrodes extending in a first direction, and thirdand fourth outer electrodes extending in a second direction to beconnected to the first and second outer electrodes, and wherein theinner electrode includes first and second inner electrodes interposedbetween the third and fourth outer electrodes and formed in the seconddirection to connect the first outer electrode to the second outerelectrode.
 12. The light emitting device of claim 1, wherein the outerelectrode includes first and second outer electrodes extending in afirst direction, and third and fourth outer electrodes extending in asecond direction to be connected to the first and second outerelectrodes, and wherein the inner electrode includes first and secondinner electrodes which are interposed between the third and fourth outerelectrodes and formed in the second direction to connect the first outerelectrode to the second outer electrode, and a third inner electrode,which is interposed between the first and second outer electrodes andformed in the first direction to connect the third outer electrode tothe fourth outer electrode.
 13. The light emitting device of claim 12,wherein a distance between the first outer electrode and the third innerelectrode is greater than a distance between the second outer electrodeand the third inner electrode.
 14. The light emitting device of claim 1,wherein the outer electrode includes first and second outer electrodesextending in a first direction, and third and fourth outer electrodesextending in a second direction to be connected to the first and secondouter electrodes, and wherein the inner electrode includes first,second, and third inner electrodes which are interposed between thethird and fourth outer electrodes and formed in the second direction toconnect the first outer electrode to the second outer electrode, and afourth inner electrode, which is interposed between the first and secondouter electrodes and formed in the first direction to connect the thirdouter electrode to the fourth outer electrode.
 15. The light emittingdevice of claim 14, wherein a distance between the first outer electrodeand the fourth inner electrode is greater than a distance between thesecond outer electrode and the fourth inner electrode.
 16. A lightemitting device package comprising: a package body, first and secondelectrodes installed in the package body, and a light emitting deviceinstalled in the package body to be electrically connected to the firstand second electrodes, wherein the light emitting device includes aconductive support substrate, a light emitting structure layer on theconductive support substrate, a protection layer provided on an outerperiphery portion of the conductive support substrate, a portion of theprotection layer being interposed between the conductive supportsubstrate and the light emitting structure layer, and an electrodehaving at least a portion overlapping with the protection layer on thelight emitting structure layer, and wherein the electrode includes anouter electrode, an inner electrode provided in a region surrounded bythe outer electrode and connecting a first part of the outer electrodewith a second part of the outer electrode, and a pad unit connected tothe outer electrode.
 17. The light emitting device package of claim 16,wherein at least a portion of the outer electrode has a width greaterthan a width of another portion of the outer electrode.